You might associate old age with frailty. It can be a scary thing to approach if you can only picture canes and walkers. But you can avoid a fate of glass-like bones much easier than you think.

According to a new study of the effects of exercise on aging, older people resemble much younger people physiologically — but only if they're active.

A team of researchers at King's College London recruited 125 fit amateur cyclists (85 male and 41 female) between the ages of 55 and 79 and tested a wide range of physical functions commonly associated with aging, such as aerobic fitness, resting heart rate, skeletal mass, breathing ability, and muscle density.

To be picked for the study, volunteers had to be able to cycle approximately 62 miles in under 6.5 hours and about 37 miles in 5.5 hours.

Smokers, heavy drinkers, and those with high blood pressure or other health conditions were excluded.

The scientists ran the volunteers through a wide array of physical and cognitive tests. They also measured the time taken to stand from a chair, walk three meters, turn, walk back, and sit down, which is is an important test of function in older people.

They found that people aged 79 and those aged 55 were equally as fit as long as they maintained similar levels of exercise.

On almost all measures, physical condition remained pretty constant across all ages. Even the oldest cyclists had younger people's levels of balance, reflexes, metabolic health, and memory ability.

Professor Stephen Harridge, senior author of the study, said in a press release:

Because most of the population is largely sedentary, the tendency is to assume that inactivity is the inevitable condition for humans. However, given that our genetic inheritance stems from a period when high levels of physical activity were the likely norm, being physically active should be considered to play an essential role in maintaining health and wellbeing throughout life.

But some aspects of aging were apparent in the study. The oldest cyclists had less muscular power, mass, and lower overall aerobic capacities in comparison to the younger cyclists.

The biggest thing to take away from this study is that how we age, to a large degree, is up to us. Aging is clearly different in those who stay active. On paper, all the cyclists in the study looked pretty young.

Your body's systems don't want to sit still — they'll deteriorate that way. So if you keep on moving as you age, your muscles, heart, lungs, and really all your body parts will thank you, by reducing your risk of disease and maintaining your health.